TDC reset, how do you do it?

[Trout]

If I want to attack two ships in a convoy, how do I reset my TDC between shots?
(I'm using full manual targeting)

It always seems my target values for the second ship are WAY off, as the torpedos go in odd directions.

Trout

[mookiemookie]

Be sure to turn off your position keeper after shooting at the first ship.

[Trout]

thats it? Just turn off the PK?

[Bando]

Yep, punch in the new values for the second one, engage, good to go

[tater]

The PK can be extremely useful, and also can result in wasting torps if you are being sloppy. I set up a second target quickly after shooting 3 tubes, and forgot to reset the PK. I sent a new spread into the burning wreck of a small passenger liner, lol.

It is cool though. Say you fire a couple fish at a merchant, then quickly set up on another in the group. Until you reset the PK, you are still aimed (gyro wise) at the 1st target, if the first fish premature, you can just shoot more at the standing PK evolving until you reset.

tater

[Uber Gruber]

I'm just curious but wouldn't entering the range, speed and AOB of a new target effectively reset it with the new target data ?

Or do you really have to click on the red light to make it go off and on again ?

I seem to be doing quite well just by inputting the new target data.

[LukeFF]

I'm just curious but wouldn't entering the range, speed and AOB of a new target effectively reset it with the new target data ?

No

Or do you really have to click on the red light to make it go off and on again ?

Yes

[XLjedi]

That's the biggest difference in my tactics between SH3 & 4... the disconnect between the aiming wire and the torpedo gyro setting.

Still haven't really found a method that I'm completely happy with in SH4 but I continue to experiment... :hmm:

[maerean_m]

It always seems my target values for the second ship are WAY off, as the torpedos go in odd directions.

The position keeper must be activated only when you have sent fresh information to TDC: range & bearing, speed & AOB.

So after you sink a ship, you deactivate the PK and only reactivate it after you have completely described the new target.

Otherwise, your torpedoes will go in odd direction because after you send the first range measurement, the PK will change the TDC data using the last's ship AOB and speed. And there can be many seconds until you determine the new AOB and speed.

Remember: the Position Keeper was a mechanical calculator with toothed wheels, not a wizard, able to eliminate the bad targeting techniques. Its only purpose was to evolve the mathematical equation of the target's trajectory, but only after you have solved it at least once. This only allows for fewer raisings of the scope to avoid unnecessary exposure.

[WernerSobe]

You dont need to reset it at all.

Just aim for next vessel and put in new data. You must make sure the target was identified and that you send the range last.

This is why it works: PK can be corrected on the fly. That means when its running and you are not happy with something like the speed or AoB, you can just put new data and the position keeper will update the solution. You can also update the ships actual location by sending new bearing and range to position keeper.

Sending range also provides bearing where your periscope optics are aiming at. So sending AoB will just update the solution with new AoB. Sending Speed will update the solution with just new speed. Sending Range will update the Solution with bearing and range so basicly it will provide a new location.

[Uber Gruber]

You dont need to reset it at all.

Just aim for next vessel and put in new data. You must make sure the target was identified and that you send the range last.

This is why it works: PK can be corrected on the fly. That means when its running and you are not happy with something like the speed or AoB, you can just put new data and the position keeper will update the solution. You can also update the ships actual location by sending new bearing and range to position keeper.

Sending range also provides bearing where your periscope optics are aiming at. So sending AoB will just update the solution with new AoB. Sending Speed will update the solution with just new speed. Sending Range will update the Solution with bearing and range so basicly it will provide a new location.
A have to agree, this is exactly how i've been doing it and i've had complete success. I fire at one tagert, leave the PK on, ID new target then send range and aob, wait a few seconds, then send range again and get speed estimate (of course I may already know the speed i.e convoy) and enter it.

The PK then has enough info to accurately track the new target....without ever turning PK off.

EDIT: I only use manual targeting.

[maerean_m]

You're right.

... If you're fast in getting the new data for the TDC.


Let us suppose you attack a ship that's going to the left, fast. You sink it.


After that, let us suppose you attack a ship that's going to the right, fast. If you leave the PK on and you do 2 range measurements and then estimate speed (but you are not so fast in using the game's interface), by the time you send the new AOB to the TDC the position keeper has already moved your target far away to the left, although the new ship is going to the right.

So you always need to do a last range&bearing measurement before you start launching torpedoes OR you turn the PK off until you completely resend all data to the TDC.

[Uber Gruber]

Phew...thanks maerean_m, thought I was going mad there for a moment.

I tend to:
1) take 1st range/bearing, send to TDC
2) Estimate AOB, send to TDC
3) take 2nd range/bearing, send to TDC
4) Get Speed estimate.

I do (1) and (2) very quickly, then wait for (3). I also tend to repeat (3) and (4) a couple of times to get a good speed estimate.

I also always do a final (1) and (2) before firing torpedo. Probably not the best tactics but they worked well for me in SH3.

[WernerSobe]

wait with AoB until you have the second mark and know the true course. Then you dont need estimate it but just read the true target course dial on TDC and set up the AoB according to that.

[Uber Gruber]

@werner

Thats a good point. Just curious though, if the second target was heading in the opposite direction then wouldn't setting the AOB before the second range/bearing mark help the PK to judge better..if it was previously set for the first target ?

Actually, now I think about it, it probably doesn't take AOB into consideration at this stage.

[WernerSobe]

It doesnt matter how bad the solution is until you fire the fish. And you can correct the sollution at any time.

So leaving the position keeper turning even with wrong data will not screw your firing solution that you have not set up yet. So let the position keeper going, and put the new dataset one by one. Just make sure you resend the range last because it also sends the bearing. You want the position keeper to start calculations with the right bearing right?

[Powerthighs]

Correct that you don't have to reset it. I usually leave the TDC on for the entire patrol.

Once you have speed and AOB set correctly, one last range/bearing input will ensure the PK is tracking accurately. If you ever change speed or AOB you need to do another range/bearing input.

All that matters is that the PK is correct by the time you shoot. Inaccuracies while setting up a solution don't matter.

[EDIT] I basically seconded what Werner said above.

[Powerthighs]

Another way to look at it is range/bearing tells the PK where the target is now. Speed and AOB tell the PK how the target will move in the future.

Once you have Speed and AOB set correctly (the ability to know future movement), one last range/bearing input (the current positition) will make the PK solution accurate, regardless of how much it was wrong due to previous activity or previous targets.

[Chakal]

You dont need to reset it at all.

Just aim for next vessel and put in new data. You must make sure the target was identified and that you send the range last.

This is why it works: PK can be corrected on the fly. That means when its running and you are not happy with something like the speed or AoB, you can just put new data and the position keeper will update the solution. You can also update the ships actual location by sending new bearing and range to position keeper.

Sending range also provides bearing where your periscope optics are aiming at. So sending AoB will just update the solution with new AoB. Sending Speed will update the solution with just new speed. Sending Range will update the Solution with bearing and range so basicly it will provide a new location.

So if I understand, you need to update the AOB for each targets you are aiming to! Even in Convoy??

In SH3, in a convoy situation, the TDC was linked with the periscope ( red/green nob). After you had find the AOB for one target, you had just to point another target with the periscope to get and updated AOB for that target.

And in the "Fast 90" targeting way, where you set ur course perpendiculary to the course of the target with AOB = 90 ( port or Starb..) at bearing 0, the AOB of the target was updated only by pointing it with the periscope.

This option of linking or unlinking the TDC with the periscope was very usefull in SH3, specialy in a "sonar only attack" or a Sub vs Sub fight where you conduct ur attack only from the attack map with the TDC unlinked to the periscope. It was then possible to enter a bearing in the TDC only by turning its nob.

So all this is absent in SH4 ??

Is it possible to enter a bearing directly in the TDC without using periscope or the "send to TDC" button from the sonar ?

Im new to SH4 ( got my copy only 2 days ago) and I dont understand yet how the position Keeper works. Maybe thats why the Note Pad miss me that much...lol

[Joe S]

I am still experimenting with TDC procedure and havent found one yet that I really like. My main objection is the inability to manually set the range. If there is a way to do it, I would apprecitat it if someone could let me know. For example, in the rare case where you actually have time to track a target for a while, if the tdc plot is not tracking properly and you know your solution needs adjustment, you can manually adjust the aob and speed estimates, but there is no way to make an adjustment for the range, because as far as I can tell, the only way to enter range is by the split image method, and if your boat is bouncing and you get a result you know is not correct, you are stuck with it until you get a chance to do it over, which means exposing the scope more than you want to. Joe S

[Frederf]

You can enter a manual range by dragging the bug on the TDC wheel, unfortunately it has a limit of ~1200 yards when setting manually.

The PK doesn't need to be turned off and on or reset between changing targets and entering new target data neccisarily BUT BE AWARE the data you enter is going to be evolved from the second you enter it.

So maybe the old data was:
Bearing 30 degrees
Range 300 yards
AOB 90 Right
Speed 21 kts

And the new data is:
Bearing 0 degrees
Range 1000 yards
AOB 0 degrees
Speed 2 kts

The second you update the bearing/range, the PK will try to evolve your data according to its picture in the middle of your update process. So it'll think briefly that the target is ahead of you, abeam, and going very fast to the right, screwing up the nice correct data you inputted before you update the AOB and Speed.

[odjig292]

I'm glad to find this thread. I'm a noob that has been combing the archives to get an answer to manual targeting after the first ship. I find the process is inconsistent as are the answers. Everyone seems to have a different solution. The first target is generally routine. The problem is when you switch to a second or third target.

I take bearings on the second ship and enter to the TDC. The PK is off. I check the torpedo solution (green line) in the Attack map before I fire and find that it can be right on, or still tracking the first ship, or curving anywhere. Sometime engaging the PK corrects it, sometimes it doesn't. The only way I've found to clear a bad solution so far is to lower the periscope until the Attack map clears and start over. It's not the road to survival when there are three destroyers circling.

I would hope that a modder (or V1.4) can give us a button to push after we have taken a bearing on a locked target that clears the previous torpedo solution, zeros out the need for speed or distance settings, and launches a selected bow or stern torpedo up that bearing FAST. It would only be good for very close shots or when you need to put a torpedo "down the throat". Killer Kane in Wahoo could do that in real life. Why shouldn't we be able to the same?

[amurph182]

I find engaging multiple targets to be fairly easy.

Using SH4 1.3 and TM1.5, the most common multiple ship encounter I have is the two ship convoy (if it can be called that). My method of attack is as follows:

1) identify both targets. decide which is the primary and which is the secondary target, usually based on tonnage but sometimes I will not be in a good attack position because of a target course change and so must go after whichever presents the best opportunity.

2) begin tracking primary:
a) get range
b) wait a few minutes, get range again
c) determine course and speed
d) based on course, enter AOB
e) activate PK

3) decide which torpedos to fire at each target. Set torpedo depth and speed, open tubes.

4) when ready to fire, raise scope one last time for last second bearing and range check.

5) fire on primary target.

6) switch to secondary. you already know the course and speed of the target, so all you have to do is get a range and then adjust AOB, which is simply a matter of adjusting the AOB dial until the TDC shows the correct target course.

7) fire on secondary target, and begin manuevering for follow-up shots from stern tubes if required.

If the sea is calm, I can fire my first torp at the second target within 5 seconds of firing the last torp at the primary. It helps that you can point the scope at whatever you want, and can even get range before you're done shooting at the first target. Until you actually send the data to the TDC, the PK tracks the first target. In heavy seas, it's obvously not as quick.


The only time I have problems here is when the convoy makes a course change in the middle of my approach, then you have to wait for all of your targets to get on the same course. And when the seas are rough, you need more time to get the range so it can screw up your planning.

If I time it right, it's not too hard to have your torps hit both targets at the same time, although sometimes that means firing at the smaller target first which can cause your solution for the second target to be rushed and mabe a bit off.

Something I haven't tried yet but want to: firing a spread at a convoy without aiming at particular ships. Get a solution on a ship in the middle, and then fire all ten tubes only making torpedo gyro adjustments, and then see how many I can hit. From my reading, this was done often when engaging convoys on the surface at night, when you didn't have time to set up on each individual ship and just needed to hit whatever you could.

[amurph182]

I would hope that a modder (or V1.4) can give us a button to push after we have taken a bearing on a locked target that clears the previous torpedo solution, zeros out the need for speed or distance settings, and launches a selected bow or stern torpedo up that bearing FAST. It would only be good for very close shots or when you need to put a torpedo "down the throat". Killer Kane in Wahoo could do that in real life. Why shouldn't we be able to the same?

you can do this easily as well.

if you need to shoot FAST, then you usually need to do this when a DD is coming right at you with a bone in its teeth. So bearing to target won't change much. Just take a quick range estimate...it won't be correct since you likely didn't identify the ship. But it sends bearing to the TDC. Set speed to zero, and then AOB doesn't matter either. Voila, torp shot down bearing. If you practice, you can do it in a couple seconds. open door, set depth the shallow and speed to high. Target speed 0. Bearing...MARK. FIRE ONE!

If you're good at estimating range and speed on sight, you can put them in manually. I'm not good at this, so I don't bother and my accuracy probably suffers.

it's not accurate at all if the target is on your beam, but if he's within 30 degrees of your bow or stern, it works often enough for me and out to 45 degrees I can get lucky.

either way, simply entering range with zero speed will send a torp down that bearing.

[Trout]

so, to summarize....


As long as you get a final range reading and send it to the TDC before firing, you can just leave the PK on.

Sending range data is how the TDC knows the bearing to target (cool to know, since now I'll try some snap shots!)

Trout

[amurph182]

so, to summarize....


As long as you get a final range reading and send it to the TDC before firing, you can just leave the PK on.

Sending range data is how the TDC knows the bearing to target (cool to know, since now I'll try some snap shots!)

Trout

correct, as long as you have updated the other information first.

[odjig292]

I'll try what you suggest. I was being served as lunch with three destroyers circling and torpedo shots were going wide because of previous solutions I couldn't get rid of. http://i12tinypic.com61o8dup.jpg

[amurph182]

I'll try what you suggest. I was being served as lunch with three destroyers circling and torpedo shots were going wide because of previous solutions I couldn't get rid of. http://i12tinypic.com61o8dup.jpg


if they're circling then my method won't help you as it is for use when there is little to no bearing change. If they're not charging directly at you, then the torp will go down the bearing you give the tdc but the ship won't be there. The reason my method for snapshots works at all is because the speed is set to zero. If you fire at a target with an AOB more than a couple of degrees, you'll miss unless you're extremely close.

Remember that if you simply turn off the PK then the TDC will just shoot with whatever info you've put into the system. So if you have DD's circling you, and using the same pattern over and over, then you can set up the shot ahead of time for the AOB and speed that you expect the target to be at when you want to shoot and just take a last second range estimate and shoot.

ex: the three DD's are circling you, and they keep crossing your stern at 90AOB and look like they're doing 10kts. So you set speed 10 and AOB 90 into the tdc with the PK off, and then when one gets into that position you just range him and shoot. They're so close that even if you're off with speed and AOB you still have a good chance at a hit if you're at least in the ballpark.

if they're too far away for that, then you probably have enough time to set up a proper solution or go deep. And if they're charging right in on you and almost on top of you, then just shooting down a given bearing is acceptable.

[odjig292]

I twice tried using the TDC to calculate speed and got "not enough data". I haven't installed TM1.4 yet. Does it correct this?

I tried the Samar short mission to test your ideas. The three shots at the Kongo went well and I was able to switch to the Yamato. I put two into it. Both were dead in the water and I circled to bring stern tubes to bear but I could not get the torpedo solution to change to finish them off. I clicked the Range and Bearing settings over and over as well as activated and deactivated the PK twice before the screen crashed.

After cleaning dead files and freeing up RAM, I went back to the scenario. Somewhat similar experience but sunk the Kongo and was focusing on the Yamato when I got run over by a destroyer that took out torpedo tubes, periscope, etc. I could not change the torpedo setting to fire at him. Then a phone call came in from China that blew the session. I must be doing something wrong but I don't know what. I cannot clear the torpedo solutions on the attack map after the second ship. I've loaded the program and V1.3 three times and no change.

I'm using a 3.1 GHz Celeron, 1MB ram and ATI 1550X 512MB grahics card and running on LOW resolution with minimum features. Why can't I clear the previous solutions? There is no sense in playing the game until I figure out what I'm doing wrong.

[Powerthighs]

It's not supposed to be easy to fire at ships that are manuevering.

To do a snapshot, just turn off the position keeper, set the target speed to zero, point the periscope at the bearing you want to fire on and click the "send range" button. You will have to estimate when to fire and how much to lead the target. There is a good chance you will miss.

It's not realistic to expect to take out ships left and right as they are circling you and aware of your presence. Success came, both historically and in the game, when taking advantage of stealth to develop your firing solution undetected. Once they are aware of your presence you no longer have the advantage.

[amurph182]

I twice tried using the TDC to calculate speed and got "not enough data". I haven't installed TM1.4 yet. Does it correct this?


you have to take at least two ranges. You identify the target, range it and send the range data to the TDC. Wait a few minutes (I usually wait 3-5) and then range it again and send the data to the TDC. THEN hit the button to calculate speed.

If you only take one range measurement or you don't send the range data to the TDC then you won't get the speed estimate.

Both were dead in the water and I circled to bring stern tubes to bear but I could not get the torpedo solution to change to finish them off. I clicked the Range and Bearing settings over and over as well as activated and deactivated the PK twice before the screen crashed.

you must be doing something wrong here. If they are dead in the water, then you just set the speed to zero and in theory you don't even need to set the AOB. Even with the PK on, when you take a new range and send it to the TDC it will update the range and bearing of the solution.

Are you not hitting the button to send the data to the TDC? Or are you not changing the speed to zero for your motionless targets?

You don't need to zero out the tdc or turn off the pk, when you have updated all of the settings the pk will simply track the target that your settings describe. If the PK is tracking a target at 1000 yards, bearing 000, AOB 90P, course 270, speed 5, and you change the AOB to 90S, the PK begins tracking a target at 1000 yards, bearing 000, course 090, speed 5. It updates those variables over time to show the motion of the target, but if you then change the range, bearing, AOB and speed it begins tracking from the last input you made.

THe only thing the PK does is show the current position of the target based upon the last entry you made. Whenever you change something it is basically the same thing as creating an entirely new solution.

Why can't I clear the previous solutions?

there are no "previous solutions." There is only one solution, and it is based off of the last information entered. The PK doesn't keep track of previous inputs, it just shows the target's position based on last input. Every data input is a new solution, and the pk tracks from that point.

What it CAN do is screw up your measurements if you don't put them in fast enough. Since it is tracking a moving target, the variables are constantly changing. If you switch to a different target and put in range, it will track a target with the same AOB and speed as the previous target but with the new range. Until you put in the correct AOB and speed for the new target it will change the range and bearing based upon the old info. Of course, once the new info is entered you can simply take a new range and it will be fine.

[amurph182]

now I have a question of my own:

when using the estimate speed function of patch 1.3, the estimate comes from your range and bearing inputs. If you enter range correctly, you get a correct course and speed estimate. I've found it to work beautifully.

I've also found that when I enter range incorrectly I get CRAZY course and speed estimates. And I would expect that, as it is only giving me an estimate based upon my inputs.

My question is how many of the previous inputs does it use when estimating course and speed? Just the last two? The last 5? All of them in the last X minutes?

The situation I'm thinking of is if I am tracking target A and decide to switch to target B, which is moving in a different direction at a different speed, and I take two range and bearing measurements will I get the correct course and speed? Or will the speed estimate be made with ALL of my inputs and thus provide me with some nutty course and speed info?

[fireship4]

I remember someone telling me that it was just the last two but dont take my word for it.

[Rockin Robbins]

I agree with Werner. Resetting the PK is definitely not necessary at all. It is VERY important, however, to enter new information in the proper order to get good targeting. This is true whether or not you reset the PK.

Let's trace the reasoning for my weird opinion, but first the gospel:

1. determine target course and speed
2. enter target speed into the TDC first
3. then enter course or AoB into TDC second
4. enter range/bearing into TDC LAST!!!

Why?

Let's do it wrong and trace the result, step by step, assuming you start tracking an original target accurately. As we begin you can see the aiming point in your attack screen superimposed on the target position, following it pretty perfectly in course and speed. Let's switch targets the wrong way.

Wrong #1: we'll take range and bearing of the new target and hit the send button.
Result: for a split second the aiming point shown in your attack screen is perfectly superimposed on your new target, but it runs away at the course and speed of the old target!

Wrong #2: we enter the speed of the new target. Result: the aiming point, which has had time to wander away from your new target is now traveling away from your new target on the old target's course, but at the new target's speed. Things are NOT getting better here.

Wrong #3: finally, we enter the course/AoB of the new target. Result: our aiming point no longer is diverging from our target. Having the correct course and speed, it merely keeps its present distance on a parallel course. Any torpedoes shot will sink that mythical hole in the water as projected on your attack screen.

Whatever order you enter the new course and speed, you MUST ENTER THE RANGE/BEARING LAST! Only then will the projected impact point be superimposed on your target. Turning the PK off and back on is completely unnecessary, and in fact will give you a false sense of security because it fixes nothing if you enter the information in the wrong order.

Why? Same thought experiment. We've reset the PK. TDC shows speed 0, AoB 0, range 0. Lets do the steps in the wrong order again.

Wrong #1. Aim at the target, get the range, hit the send bearing/range button. Result: for a split second your aiming point on the attack screen is accurate, but it has speed zero. The real target runs away from your aiming point.

Wrong #2: determine target course and either enter that directly or enter AoB. Result: nothing changes. The aiming poing is still stationary as an object with zero speed can't respond to a new course.

Wrong #3: we finally enter the speed: Result: the aiming point is on that parallel course but not coincident with the target.

Again, entering the range/bearing last is the key to manual targeting. I don't have a clue why nobody has called attention to this in the past. I hope that I have not only laid the misconceptions to rest but proven my case to everyone's satisfaction. Thanks Werner for getting me hooked on this stuff!

[brandtryan]

Yup, I had to watch Werner's videos a few times--but now I "get it", and have had some good success' as a result.

[jazman]

This is Sub(sim) School. Your homework is now to practice this stuff until you understand it enough to explain it.

[letterboy1]

Well, I just did some homework with Amurph's lesson in this thread for engaging two targets with manual TDC. Long story short, I fired 3 fish on slow speed at the front merchant when he was at AoB=0, then swung the scope to the following merchant and, after putting his identity in the TDC, I ranged him, entered new AoB and fired 3 fish at fast speed. As torpedo 4, 5, and 6 were leaving their tubes, numbers 1,2, and 3 were hitting the front ship. The second ship didn't have enough time to maneuver before all three fish hit him as well.

This thread has been most usefull. Thanks!:up:

[jazman]

Well, I just did some homework with Amurph's lesson in this thread for engaging two targets with manual TDC. Long story short, I fired 3 fish on slow speed at the front merchant when he was at AoB=0, then swung the scope to the following merchant and, after putting his identity in the TDC, I ranged him, entered new AoB and fired 3 fish at fast speed. As torpedo 4, 5, and 6 were leaving their tubes, numbers 1,2, and 3 were hitting the front ship. The second ship didn't have enough time to maneuver before all three fish hit him as well.


You have graduated, summa cum laude. :up:

[Fincuan]

...after putting his identity in the TDC, I ranged him, entered new AoB and fired 3 fish at fast speed...

It's also possible to identify all the targets beforehand, so that you only have to lock him, get the range, enter AOB and fire.

[Rockin Robbins]

Well, I just did some homework with Amurph's lesson in this thread for engaging two targets with manual TDC. Long story short, I fired 3 fish on slow speed at the front merchant when he was at AoB=0, then swung the scope to the following merchant and, after putting his identity in the TDC, I ranged him, entered new AoB and fired 3 fish at fast speed. As torpedo 4, 5, and 6 were leaving their tubes, numbers 1,2, and 3 were hitting the front ship. The second ship didn't have enough time to maneuver before all three fish hit him as well.

This thread has been most usefull. Thanks!:up:
Congratulations!!!! There's nothing more satisfying (except maybe a sonar-only kill) than bagging a double kill!:rock:
http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/SH4Img23-8-2007_733.15_859.jpg

[Fincuan]

Congratulations!!!! There's nothing more satisfying (except maybe a sonar-only kill) than bagging a double kill!:rock:

True, but only if we are limited to SH4! The next step is a sonar-only double kill with radar-only approach :up: It's quite exciting to look at the stopwatch and wait for the torps to hit, and then check the logbook to see what it was that you hit, since you never saw the targets.

[letterboy1]

Thanks, guys!:know: And Fincuan, good call on that . . . I didn't think to try ID-ing the target before-hand.:up: